1. Field of the Invention
The invention relates to an apparatus for the preparation or extraction of samples, especially for analytical purposes, from a liquid or using a carrier liquid.
2. Description of the Related Art
The separation of a sample in this manner is known, for example, in flow-injection analysis in which filtration, dilution, concentration, extraction, chemical reaction or some other known procedure is carried out. There are difficulties, however, in such a preparation or extraction or separation of samples from liquid, aqueous or biological-aqueous media, since the separation of sample molecules according to electrical charge or according to ionic mobilities is generally difficult or even impossible.